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Adiabatic calorimetry of a very low density polyethylene copolymer

Domenii publicaţii > Chimie + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: J.C. van Miltenburg, V.B.F. Mathot, P.J. van Ekeren and L.D. Ionescu.

Editorial: J. Therm. Anal. Cal., 56, p.1017-1023, 1999.

Rezumat:

The heat capacities of a very low-density polyethylene copolymer (VLDPE) was measured between 10 and 410 K. The glass transition takes place from roughly 205 to 225 K and is centred around approximately 215 K. Using two sets of literature data for the fully crystalline and the fully amorphous states, crystallinities were calculated as a function of temperature. During the stabilisation periods in the melting process no equilibrium is reached, because of an exothermic process, which is attributed to (re)crystallazation. Values for the enthalpy of melting and for the heat capacity of the liquid are given.

Cuvinte cheie: adiabatic calorimetry, calorimetry, crystallinity, polyethylene, VLDPE, heat capacity, recrystallisation, relaxation